The present invention relates to apparatus used by scuba diver's, and in particular, to an improved device in which an inflatable bladder is used to adjust a diver's buoyancy.
Buoyancy control devices have long been used by diver's to regulate their buoyancy during the course of a dive. Often a diver needs to have neutral buoyancy so that the diver may easily control his or her movement underwater simply by walking or swimming. Alternatively, a diver may want to dive "heavy" if there is substantial current in order to stay on or near the bottom. Conversely, a diver may desire positive buoyancy in order to float on the surface upon conclusion of a dive.
The earliest known example of a diver's buoyancy control device is disclosed in U.S. Pat. No. 40,114 granted to T. C. McKeen in 1863, during the American Civil War. That device was designed to be worn on a diver's back and included an inflatable bladder.
The advent of scuba diving during World War II led to the development of more sophisticated devices for regulating a diver's buoyancy. Both wet and dry suits used by scuba divers add substantial positive buoyancy which can be counteracted by a weight belt. However, the need for precise buoyancy regulation during scuba diving results from changes in a diver's weight and water displacement over time and at different depths. The diver's weight and water displacement will change as a result of compression or expansion of trapped gas in the cells of the diver's wet suit or dry suit as the depth of the dive increases or decreases. In addition during an average scuba dive the diver loses approximately six pounds in weight because compressed breathable gas is consumed by the diver from his or her scuba tank. In addition to compensating for changes in buoyancy due to changes in the diver's weight and water displacement, the diver may also want to change his or her buoyancy to dive heavy or float, as previously described.
Modern diver's buoyancy control devices typically comprise an inflatable bladder worn on the diver's back and a manual control actuated by the diver to add gas to the bladder from the scuba tank or to vent gas from the bladder into the water. Typically the manual control is associated with a hose that connects to a fitting on the diver's regulator and to the bladder. For example, in my U.S. Pat. No. 5,620,282 entitled BUOYANCY COMPENSATOR ASSEMBLY granted Apr. 15, 1997 there is disclosed a diver's buoyancy control device with a special passageway for guiding hoses that extend between the scuba tank regulator, the manual control and the bladder. This configuration reduces the possibility of entanglement of the hoses which can lead to a diving accident.
Diver's buoyancy control devices are fairly complex and expensive items which must function correctly to enable a comfortable free dive, but which also must function correctly to avoid a serious accident. Presently they must be manufactured in a variety of sizes for small, medium and large stature men and women. In addition, buoyancy control devices must presently be tailored to either provide neutral buoyancy during a dive, or to have the additional capability of providing substantial surface flotation. They must also be configured to be worn with and without a weight belt. The weight belt must not only be separately donned, but in addition, must be accessible for emergency release. It would be desirable to provide an improved diver's buoyancy control device which could be adjusted to fit a larger range of diver sizes, while at the same time being configured to more easily cooperate with a weight belt and provide the option for substantial surface flotation.